Mars Reconnaissance Orbiter (MRO)
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Psp_002839_1825_red.jpgAram Chaos' Sediments (False Colors)53 visiteAram Chaos appears to be a former impact crater. The terrain is disrupted, giving it a chaotic appearance (hence the name "chaos"). Scientists have postulated that a lake may have once existed inside the crater and sediments were laid down within the lake.
The mineral Hematite (rich in Iron) has been detected by orbiting spacecraft within Aram Chaos. Hematite has been identified in several other locations on Mars, including at the MER Landing Site in Meridiani Planum. The Hematite at both Meridiani and Aram Chaos most likely formed by precipitation in water.
This HiRISE image shows the light-toned sediments inside Aram Chaos that could have formed in a former lake. Unfortunately, dark debris now obscures much of this sediment, making it difficult to view and interpret the rocks. The light-toned layered deposit in the south (Dx) of the image is higher standing and has a pitted surface.
Circular structures with dark centers are likely to be impact craters that have been partly filled with dark debris, including sand. More irregular depressions appear to result from erosion of layered beds within the sediments. Wind could erode materials that are slightly weaker more quickly and produce the irregular topography seen along the surface of the deposit.
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TRA_000825_2665_IRB.jpgNorth Polar Layered Deposits (full image & HR)53 visiteThis image of the north polar layered deposits was taken during the summer season (solar longitude of 113.6 degrees), when carbon dioxide frost had evaporated from the surface. The bright spots seen here are most likely patches of water frost, but the location of the frost patches does not appear to controlled by topography. Layers are visible at the bottom of the image, mostly due to difference in slope between them. The variations in slope are probably caused by differences in the physical properties of the layers. Thinner layers that have previously been observed in these deposits are visible, and may represent annual deposition of water ice and dust that is thought to form the polar layered deposits. These deposits are thought to record global climate variations on Mars, similar to ice ages on Earth. HiRISE images such as this should allow Mars' climate record to be inferred and compared with climate changes on Earth.
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TRA_000878_1410_RGB.jpgTerra Sirenum53 visiteThis region receives very little sunlight in Southern Winter, and the bluish areas consist of frost. At the latitude of this image, frost is most likely composed of water because the temperature is not low enough for CO2 condensation. The reddish regions are locations where frost has been removed, most likely by sublimation. The dark, unfrosted regions (for example, in the channel of the gully on the far right) represent the most recent activity in the gullies and are possibly a result of seasonal melting.
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PSP_001948_1425_red.jpgGorgonum Chaos (Original NASA/JPL/University of Arizona b/w Frame)53 visitePSP_001948_1425 shows part of Gorgonum Chaos, a large cluster of chaotic terrain found in the Southern Hemisphere.
Many regions of chaotic terrain are found at the head of large outflow channels that were scoured by ancient floods. Gorgonum Chaos is one region that is not associated with an outflow channel. Chaotic terrain can form when subsurface volatiles (such as water) are catastrophically released and the overlying surface collapses. It is not known whether isolated chaotic terrain such as that shown in this image formed in the same way that the chaotic terrain near the outflow channels did. Wind erosion might play a role in their formation.
Gorgonum Chaos is an especially interesting area because gullies thought to have been eroded by liquid water are located on its mesas. The gullies have a wide range of orientations and many appear to emanate from a distinct layer in the mesas.
It is not known why gullies form on one slope rather than another, but insolation (amount of sunlight received), availability of water, and regional slope are possible contributing factors.
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PSP_002244_1720_red.jpgWhite Rock (Enhanced Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga - Lunexit Team)52 visiteThis image shows a portion of a relatively bright landform named "White Rock" on the floor of Pollack Crater in the Sinus Sabaeus Region of Mars.
Data from the Mars Global Surveyor Thermal Emission Spectrometer (TES) indicates that this landform is not anomalously bright, relative to other bright Martian Regions. Further, the apparent brightness seen here is due to contrast with other materials on the crater floor.
Dunes and ripples are visible in the dark material between the bright ridges. Their orientations appear to be influenced by wind directionally channeled by the ridges. Material appears to have been shed from the white landform and deposited on the darker bedforms indicating that the light-toned outcrops break down into fine materials.
Its high albedo and location in a topographic basin have led to suggestions that White Rock is an erosional remnant of an ancient lacustrine evaporate deposit.
Other interpretations include an eroded accumulation of compacted or weakly cemented aeolian sediment.
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Psp_002098_2220_red-01.jpgMantles and Flows in Moreux Crater, with a "small" Surface Anomaly (EDM - False Colors)53 visiteSegnalataci dal Dr Barca (ottimo "occhio"!), la possibile Anomala di Superficie si sostanzia in una traccia di colore scuro che ci appare incongrua, nella sua direzione, rispetto alle altre fratture (anche modeste) della superficie ripresa, rispetto alla generale direzione assunta da dune e ripples e rispetto a tutte le altrei stratificazioni visibili.
Di che si tratta? Potrebbe essere un image-artifact (la definizione del frame, sebbene eccellente, non tale da consentirci di escludere l'ipotesi del vizio fotografico), cos come potrebbe trattarsi di una recente frattura del suolo (magari di origine sismica) o anche di uno "scalino" roccioso (un layer sedimentario parzialmente esumato).
Certo, se fossimo degli Eso-Archeologi illuminati ed immaginifici, ci saremmo gi diretti verso l'ipotesi (decidete Voi se "esotica" o meno) della "possibile evidenza di una struttura superficiale artificiale".
Ma noi non siamo Eso-Archeologi.
E, purtroppo, non siamo neppure illuminati ed immaginifici, per...per, se proprio dovessimo "azzardare"...diremmo che il rilievo scuro, in questo frame, potrebbe anche essere un'ombra. Di che cosa? Beh, questo "azzardatelo" Voi!...
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PSP_003234_2210_red.jpgThe "Face" on Mars... (False Colors; credits: NASA/JPL)90 visiteImage PSP_003234_2210 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on 05-Apr-2007.
The complete image is centered at 40,7 latitude, 350,5 East Longitude. The range to the target site was 299,4 Km (187,1 miles). At this distance the image scale is 29,9 cm/pixel (with 1 x 1 binning) so objects ~90 cm across are resolved.
The image shown here has been map-projected to 25 cm/pixel and north is up.
The image was taken at a local Mars time of 03:28 PM and the scene is illuminated from the West with a solar incidence angle of 73, thus the Sun was about 17 above the horizon.
At a Solar Longitude of 213,4, the season on Mars is Northern Autumn.
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PSP_002917_2175_RED_browse.jpgCrater Cluster in the Northern (Mid-Latitude) Plains52 visiteA Northern Mid-Latitude scene consisting of craters, intercrater plains and mantled material is seen in PSP_002917_2175. The mantled material seen here covers much of the Middle Latitudes in both Hemispheres of Mars; it has been visibly removed in some locations. It's called "mantled" because it looks as if it's just draped over, or mantling, the topography underneath. The mantled material is what causes the craters to have a muted, softened appearance. It's thought to be ice-rich material deposited in a climate different from that of today.
The mantled unit is dissected here, meaning that is not pristine and has likely undergone modification since it was originally laid down. The intercrater plains have a pitted texture that is thought to be caused by water ice sublimating and leaving depressions behind.
Unlike that of Earth, the obliquity (tilt of the planet's rotation axis) of Mars changes wildly.
Earth has the Moon to keep its axis stable, but Mars' satellites, Phobos and Deimos, are not massive enough to do the same.
Today Mars' obliquity (25.19) is similar to that of Earth's (23.45), but this has not always been the case. As the obliquity changes, the portions of Mars that receive the most sunlight shift. During periods of high obliquity, polar regions receive the most sunlight. This causes polar ices, including water ice and carbon dioxide ice, to sublimate (evaporate) into the atmosphere. They would then potentially be re-deposited in the mid-latitudes, similar to where this image is located. It is believed that this process is responsible for the mid-latitude mantled unit.
MareKromium
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PSP_003193_0850_RED_browse_01.jpgMartian Spring: the "V" Fans (extra-detail mgnf)69 visitenessun commentoMareKromium
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PSP_003193_0850_RED_browse_00.jpgMartian Spring: the "V" Fans (context image)52 visiteSouthern Spring sunshine is causing the seasonal Carbon Dioxide (CO2) Cap at the South Pole to evaporate.
This process happens fitfully, as small and large spots expose bare ground, which warms up, causing small spots to grow.
The defrosting areas are controlled by small scale differences in topography, which cause some areas of frost to be sheltered longer than others.
Once dust has accessed the surface it is blown in directions controlled by the local winds, making a distinctive fan. When the wind changes direction the fans broaden or may show multiple orientations.
It has also been proposed that dust is carried to the top of translucent seasonal carbon dioxide ice by release of gas held under pressure by the ice cap. When the pressure is released, like pulling the cork out of a champagne bottle, the gas escapes, carrying dust with it.MareKromium
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PSP_003222_1565_RED_browse.jpgProposed MSL Site in Eberswalde Crater52 visitenessun commentoMareKromium
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PSP_003368_1755_RED_browse.jpgProposed MSL Site in Juventae Chasma (detail of the so-called "Martian Handwriting")109 visiteForse qualche Lettore avr gi riconosciuto il luogo e l'oggetto di questa ripresa e forse no.
Nel dubbio, Vi diciamo che si dovrebbe trattare (il condizionale d'obbligo, poich non abbiamo le coordinate esatte al centesimo di grado e quindi potremmo anche sbagliarci - ma di poco...) di una porzione della famosa - si fa per dire, naturalmente - "Scritta Marziana" di cui si parlato sia nel Forum di SpazioUfo.com, sia nella nostra Rubrica TruePlanets.
Nostra opinione?
Se si tratta effettivamente di una porzione della "Scritta", allora pensiamo che adesso risulter evidente a tutti come il parlare di artificialit del rilievo sia stato non solo azzardato e fuori luogo, ma addirittura ridicolo.
In caso contrario (e cio qualora questo dettaglio fosse semplicemente relativo ad una zona promiscua alla "Scritta"), un simile e spettacolare frame MRO ci deve comunque essere di aiuto per capire, una volta che esso sia stato posto a confronto con il frame ESA-Mars Express relativo alla medesima zona, che l'operare congetture usando le orrende ed extra-piallate pseudo-immagini ESA pi che periglioso: - semplicemente - assurdo.
E con questo, almeno per noi, la querelle sulla "Calligrafia Marziana"... chiusa.MareKromium
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